Process for the continuous casting of castings with continuous longitudinal hollow spaces



Dec. 17, 19-40. 5 JUNGHANS 2,225,415

PROCESS FOR THE CONTINUOUS CASTING OF CASTINGS WITH CONTINUOUS LONGITUDINAL HOLLOW SPACES I Filed May 6, 1938 2 Sheets-Sheet 1940- s. JUNGHANS 2,225,415

PROCESS FOR THE CONTINUOUS CASTING OF CASTING'S WITH CONTINUOUS LONGITUDINAL HOLLOW SPACES Filed May 6, 1938 2 Sheets-Sheet 2 Patented Dec. 17, 1940 rnocass roa 'rna cou'rmnous cAs'rmo or cAs'nNGs wrrn com'nmons Loner, woman nornow SPACES Siegfried Jnnghans, Stuttgart, Wurttemberg, Germany Application May 6, 1938, Serial No. 206,366

In Germany May 8, 1937 1 Claim. (Cl. 22200.1)

It has been already proposed to cast continuously castings with hollow spaces, in which case a mandrel or core is introduced from above into the centre of the chill mould and during the casting produces in the cross-section enclosed by the chill mould a hole which appears in the finished casting as a longitudinal hollow. This casting is therefore a pipe.

It has however been found that-this method w has the drawback that as the supply of the liquid metal has to take place laterally of the centre of the chill mould, the temperature distribution in the liquid casting head or ingate is an irregular one, for the supply side must always contain 5 a hotter metal than the opposite side. This resuits in an irregular congealing or solidification which leads in turn to irregularities in the structure of the cast metal. Another drawback is that this process can be applied only in the case of relatively large casting cross-sections, as between the core and the wall of the chill mould there must be always so much liquid metal as to make impossible solidification between the metal supply pipe and the core or the mould wall, as

otherwise the work would be interrupted on account of such freezing or solidification.

It is further known in the continuous casting of solid castings to supply the jet of molten metal to the mould in a steady uniform manner and to maintain in the centre a small liquid casting head of small depth without deep liquid blow holes or pipes, and in that way to be able always to regulate exactly the shape and the speed of the solidification. In such. a process, under the mouth of the supply pipe within the chill mould is preferably arranged a cup-shaped catching or receiving device for the purpose of ensuring in a reliable manner uniform inflow and uniform distribution of the incoming metal without any formation of pipes or blowholes.

According to the invention, the drawbacks of the process mentioned in the first place for continuous casting of hollow bodies are eliminated by maintaining also in this case over the whole cross-section of the chill mould a small liquid casting head, which therefore covers the cores provided for the purpose of producing the hollow spaces. The chill mould is therefore arranged in such a manner that the cores no longer project 0 upwards as hitherto out of the liquid casting head, but begin below the surface whilst above them the liquid metal is uniformly distributed over the whole cross-section. When'a pipe is to be cast, there is arranged in the centre of the chill mould, but below the level of the liquid casting head, a' hollow core which can be continuously cooled by means of a cooling medium; when in this-case a receiving and distributing device is to be used, as mentioned in the foregoing, the core could be arranged under it, or 5 even carrying it. Although in the latter case the core is actually introduced from the top, it is apparent that the cooling action of the core can only begin below the liquid casting head.

It should also'be apparent that in this way 10 there could also be made cast bodies with several parallel hollows by providing several cores in the chill mould below the liquid casting head. These cores could then be so constructed that they would completely separate from each other the 15 individual cast bodies, that is to say so that the latter would leave the chili mould as bodies completely independent of each other, or so that the solidified body could readily be subsequently divided into such individual bodies. Care must then be taken that the casting head extending over throughout-the whole cross-section of the chill mould should not be brought to solidification by the cores or separation bodies, or in other words, that the cores or separation bodies should 25 begin their cooling action only when a uniform liquid metal distribution over the whole chill mould cross-section throughout the casting process has been ensured.

The cores or separation bodies can be con-' 30 nected to the chill mould so that they participate in any movements of the latter during casting. 0n the other hand, they may be independent of the chill mould and stand stillvor make movea ments of their own during casting. 5

In this way small as well as large metal quantities can be cast without any difficulties arising, provided only that care is taken to ensure that the liquid casting head remains the same over the whole cross-section of the mould and thereby ensures uniform metal supply and solidification at all points of the said cross-section.

Several constructions according to the invention are diagrammatically illustrated in the drawings, partly in longitudinal section and partly in plan, as follows:

Figure 1 is a longitudinal section of one form of my invention.

Figure 1A is a plan view of the same.

Figure ,2 is a longitudinal section of a modified form.

Figure 2Ais a plan view of the same.

Figure 3 is a longitudinal section of another modified form.

Figure 3A is a plan view of the same.

modified form.

Figure 4Ais a plan view of the same. Figure 5 is a longitudinal section oi anothe J visa longitudinal section of another.

5 modified form.

Figure 5A is a planview oi the same.

Figures 6 and 7 are longitudinal sections of other modified. forms. I

Figure} is apian view of the form show din Figure 6.

; I Figure!) is. a longitudinal section of another modified form.

Figure 9A is a plan view of the same; Figure 10 is a longitudinal.sectionofanother l5 modified form. 3 Figure 10A is a plan view of thesame.

Figureil is a longitudinal sctionof another ing, to distribute it uniformly over the "whole cross-section of the chill mould. As willbe seen 1 clearly fromFigure 1, this cup I) issituated during casting intheliquid casting head :1." .Under the cupb is provided a hollow corec which has during the casting operation normally theteinperature of the metal flowing in, but which can of course be constantly internally cooled by meansof water, oil, air or the like. Both partsthe cup b and the core c-may be connected to the chili mould so that they participate inany of its "movements, ior"instance up and down move- .ments. 1

The cup orcore may be supportediri the mould in any suitable manner. Thismay be easily done by suspending the cup or core by meansof thin.

rods which extend from above the mould into the mould and through the liquid casting, head.

Such rods are indicated,for example, ate, Figures this The process of casting takes placein the following manner: The metal comingthroughthe pipe 0 passes first into the cup'b and isdistributed thence uniformly over the whole chillmould cross-section so that the liquid casting head a is formed. The metal solidifies then not'only at.

the chill mould wall but also, owing to the cooling of the core c, at the latters walls under the casting head, so that at this point there is formed in the solidiiyingcasting a hollow space correspending to the shape of the core. Asfin 'continuous casting the whole cross-section of the casting is constantlypulled down, a continuous hole will be formed through the centre of the'casting.

But in contrast to known processeathesupply th 11 ti h r i w w and B so dmca on or t 6 metal take lplace' in I tion walls or partitions c built into thechill mould aperfectly uniform manner. r

In the construction according toFigure 2, are provided thre coresc, d, e which are situated eccentrically inthe chill mould and can be connected to the latter. These coresare also'arranged so low that they are situated under' the liquid casting head; and this casting head ais not influenced by the cooling of the cores. Here again there is the. cup b, the object. of which is uniformly to distribute the metal supplied. In this way during casting is produced abody with three continuous hollows asmay be seenin plan below Figur 2. v

In known processes where the cores are introduced from the top and project upwards out of th au s distribution and more particularly temperature distribution would place even if the cup I) were provided: c flu nt limitations of .known processes are emphasised by the next ex- 5 ample. a

Figure 3 shows a core or separation body in the form of a hollowring c which is coaxia l with the chill mould. The metal infiowing through the pipe,

. a is distributed from the cup b in a uniform man 10 nor over the whole cross-section. including the top of the annular cor c.' In this way the casting fromoneand the same chill mould produces a round'solidbody hof a diameter-i corresponding to thelinsidediameter of the rinse. and fur- 15 ther apipe kwith the outside diameter corresponding to the mould, andinside. diameter corresponding to the outside diameter ofthe ring c. During one andI-the same casting process, there will be produced therefore two diiferent cast 20 bodies. If, as in the knownprocess, the annular core cwere introduced from the top and were to project out of the liquid casting head v the outer I body It wouldrnot be produced at all, as no metal could reach" it from the piped. It is therefore 25 important that according to the rule givenby the invention, the liquid casting head. should extend I uniformly overthe whole cross-section, including the coresor other separation bodies provided for the formation of the hollow spaces.

I The further development-of the invention gives i now the following result:

With the continuous process it has hitherto been impossible to go below certain cross-sections and diameters, as the supply of liquid metal was .35 impossible on purely. technicalgrounds of construction. This drawback can berelnedied accordingto the invention bytmanufacturing togetherfseveral. small cross-sections in a single chillmould so. that it will nevertheless be possible 40 to obtain a suiiiciently large casting head suitable for these purposes and common to all these casts ings. Figures 4 and 5 show. some examples of In the construction according to Figure 4, the 45 cup b is connected direct to the core 0, and both can participatein any movements of the mould. Into the mould arefitted separation bodies with corresponding cooling devices for thep rpose of obtaining individual castings from the liquid 50 casting headwextending over the whole chili mould cross+sectionr The core 0 arranged under the cunh ehsuresthen continuous separation of the individual castings, so that they leave the mould separated from each other. p t

In theconstruction according :to Figure 5, the

same obiectfisaimed at, with the difference only that here the cup b isagain rigidly secured to the metal, supply pipe 9 and ensures only uniform metal supply and distribution, whilstjtheiseparafor the manufacture of theindividual bodies, are connected together in the centreand so. arranged as to ensure thatthe common liquid casting'head shall bemaintained. The hollow: space ethus 85 formed inathe centre can be either heated. or cooled by means of any desired devices.

Conversely, it 118.81 also been hitherto impossible to cast unlimited large quantities,more,particubranches of manufacturing, for instance for the casting. of steel or other metallurgical products aaaaait 3 such as cast iron bars, copper bars, lead bars, etc., as too many installations would have been needed to cope with the large rate of supply of liquid metal. Here also the process and the apparatus according. to the invention give however a simple method, namely by building into a large common mould, in the same way as for small quantities but on a larger scale, separation partitions which are so arranged and cooled as to ensure that a 10 common liquid casting head shall be maintained during the whole duration of casting. An example of this is shown in Figure 6 in'which again the cup b is rigidly secured to the core 0 and participates with it in any movements of the mould. The core 0 and the partitions m produce hollow spaces for the castings, so that completely separate cast plates come out of the mould, as is indi-. catedin plan in Figure 8. w r

The same success is obtained with the construction according to Figure '7, but with the difference that here a core connected to the cup is dispensed with, and the separation of the liquid metal is attained by therequisite shaping of the separation bodies n extending inwards from the 25 mould wall, in the same way as in the example according to Figure 5. Here also provision can be made for maintaining correct liquidity of the casting head by heating or cooling.

Figures 9, 10 and 11 show further examples on 30 the same principles.

In the construction according to Figure 9, in a rectangular chill mould cast plates are produced completely separate from each other, whilst in the construction according to Figure 10, the plates come out. of the mould connected to a single block; By sawing or other separation, this block can be divided into its individual parts.

The construction according to Figure 11 shows the manufacture of wire rods which leave the 40 chill mould in five uniform cross-sections in the form of endless castings.

The endless plates, bars, rods, hollow bodies or other sections produced in these various ways, can be sawn, after leaving, in a manner well known in itself, into individual pieces, separated by acetylene'burners, or divided in any other desired manner. The further usual treatment 5 processes well known in themselves, can of course also be applied. It must be further pointed out that the use of a cup or the like catching device under the orifice of the supply pipe is not an absolute necessity; and that if no special value is 10 attached to obtaining a particularly uniform and homogeneous casting, the cup may also be omitted, and on the other hand (for instance in the constructions according to Figures 5 and 7) the catching devices may be omitted even when a 15 uniform homogeneous casting is to be obtained, as in sucha case the space e formed by. the partitions provides in a way for the catching of the incoming metal jet. 'Finally, such special guide devices may be dispensed with also when particularly large quantities of metal are to be cast, as for instance in the construction according to Figure 10.

Having now particularly described and ascertained the nature of my said invention, and in what manner the same is to be performed, I de-" clare that what I claim is:

Method for the continuous production of metal castings which comprises continuously pouring liquid metal into the open upper end of a mould, said liquid metal being discharged at a point below the surface of the liquid metal head in said mould, continuously forming a hollow passage in said casting by obstructing the flow of liquid metal within an interior zone extending from a point below the surface of the liquid metal head to a point immediately below the upper surface of the solidified casting, continuously cooling said interior zone, and continuously withdrawing solidified casting from the lower end of said mould. .3

SIEGFRED JUN GHAN S 

